This laboratory implements diagnostic ultrasound instrumentation in a clinical setting for non-invasive assessment of extracranial arterial disease. Real-time B-mode imaging provides two-dimensional images of major arteries and surrounding anatomy in the neck and clavicular regions. Pulsed Doppler is added in order to detect the flow velocities within those vessels visualized. The pulsed Doppler velocity waveforms acquired at specific sites within the blood vessel are compared with contrast arteriography in the disease assessment process. In addition, computer pattern recognition analyses are performed since many aspects of this procedure are ideally matched to computer iterative processing. Since instrumentation of this type is both new and complex in nature, efforts are made to facilitate instrument use and interpretation of acquired data.